Improvement in hot-air furnaces



H. M. P'H-IINNEY. Hot-Air Furnace.

No. 205,762. Patented July 9,1878.

IRIVENTUR UNITED STATES PATENT OFFICE.

IIUGII M. PIIINNEY, OF CAMBRIDGE, MASSACHUSETTS.

IMPROVEMENT IN HOT-AIR FURNACES.

Specification forming part of Letters Patent No. 205,762, dated July 9,1878; application filed November 20, 1877.

To all whom it may concern:

Be it known that I, HUGH M. PHINNEY, of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented an Improvement inFurnaces, of which the following is a specification:

This invention has for its object the followin g-describedheating-chamber, entirely surrounded by a coinbustion-chamber andprovided with a cold-air inlet and suitable hotair outlet, and also witha cone-shaped deflector arranged immediately over the cold-air inlet, sothat the cold air is caused to impinge against and contact with theheated walls of the chamber in passing through the same by being thrownagainst said walls by the deflector in a very thin current, as willhereinafter be more fully described.

In the drawing, Figure l is a vertical section of a furnace, showin g myinvention on the line as 00 of Fig. 3. Fig. 2 is another verticalsection of the same on the line y y of Fig. 3; and Fig. 3 is a plan ofthe furnace.

The chamber A is arranged within and near the top of thecombustion-chamber B, and is provided with the cold-air inlet a, thedeflector I), and the hot-air outlet 0. In practical use I design toadapt the chamber A to any of the principal furnaces on the market, asthe same may be introduced as an attachment and fitted in thecombustion-chamber with a very little modification or alteration of anyof the furnaces now in use; and, on a smaller scale, the same principlemay be used in stoves having a combustion-c]iamber of sufficient size.The chamber may be made of cast, sheet, or wrought iron, and,preferably, is constructed in detachable sections. In the drawin g, thetop plate d is shown removable.

It will be seen that the deflector spreads the amount of cold air andcauses it to contact with the heated side of the chamber in a thinvolume, and thereby greatly assists its heating property.

The ash-pit O is connected with the direct draft D leading to the lineby the pipe E, and the damper F is pivoted in the lower corner of thebox G toward the furnace, so as to act either in closing the directdraft from the fire, the indirect draft from the ash-pit, or to regulatethe proportion of the direct to the indirect draft.

The grate H is pivoted on the crossbar I to swing to and from theentrance to the ashpit K, so that the ashes and coal from the firepot,when the same is cleaned, may be deposited at the entrance to theash-pit by tipping the grate downward in that direction, therebyproviding means for the ready removal of the furnace is greatlyincreased, and that the cold air introduced into the same is veryquickly heated to a high temperature, higher than could be given the airheated in a chamber which incloses a combustion chamber, like chamber L,as the outer surface of such a chamber is exposed to the cold airsurrounding the furnace and necessarily radiates more or less heat,while the air heated in the inner chamber cannot be reduced intemperature by radiation, and can only escape therefrom through theoutlets into the pipes leading to the room above.

If desired, in addition to drawing the heat from the innerheating-chamber, the heat may be conducted from the chamber L as is donein the ordinary furnaces, as the heat is not only radiated from thecombustion-chamber into the inner-chamber A, but. also radiates into thechamber L with as great and perhaps greater intensity than if thechamber A was not used, as the heat in the combustion-chamber circulatesbetween the inner wall of chamber L and the wall of the inner chamber A,and, therefore, radiates in both direct-ions with about equal intensity.

The many advantages of this construction are too manifest to needfurther description, although it is well enough to say that by its use astove may be changed into a small furnace, and perform the double dutyof heating the room in which it is placed as well as other rooms withwhich the inner chamber may be connected by suitable piping, as the heatin the interior of a combustion-chamber cannot be utilized unlessprovided with means for radiating, substantially like that I havedescribed.

It will be observed that the cold air is sup plied the heating-chamberthrough an inlet that enters the chamber at its lowest part, at or nearthe center of the bottom plate of the chamber, so that the cold air isint-reduced int0 the chamber at its very bottom; and in a manner tosecure a quick, uniform, and direct heating of the same in its passagethrough the chamber.

It will also be seen that the deflector is placed immediately over thecold-air inlet in such a way as to cause the air in its passage throughthe heating-chamber to be spread against the wall of the chamber evenlyand uniformly.

I am aware that the patent granted Solomon Mead, December 24, 1861, No.34,003, shows and describes a system of spiral airpassages and spiralfire-fines, whereby a current of air is caused to be passed through aninterior heating-chamber spirally in a body; but this method of heatinga volume of air does not constitute my invention, as there is noprovision therein for throwing a very thin current of air uniformly andsimultaneously against the wall of a heated chamber on all sides of aninverted cone-shaped deflector arranged within said chamber immediatelyover the cold-air inlet in such a way that the air in passing the sameis not di 'erted from its direct course, but is spread into a very thincurrent, entirely inclosin g the deflector in passing directly by thesame to the exit.

I claim 1. In a furnace or heating-stove, the combination of theheatingchambcr A, entirely Slll' rounded by the combustion-chamber B,and provided with a cold-air inlet, a, and a hotair outlet, 0, and alsowith a cone-shaped deflector, 1), arranged immediately over the coldairinlet with the said combustion-chamber 11, substantially as and for thepurposes described.

2. The hereiubeforedescribed system of airpassages and drafts, togetherwith a regulatjug-damper in a box, whereby an indirectdraft opening fromthe ash-pit and a directdraft opening from the combustion-ehamber arebrought together in the box and regulated by that damper.

3. 111 a furnace or heating-stove, the comhi nation of the ash-pit O,indirect draft E, leadin g from said ash-pit directly to the directdraft, the direct draft D, opening from a combustion-cham her above thefire, and the damper F, hinged in the box G at the juncture of saiddirect and indirect drafts, as shown, to act as a regulator, asdescribed, and to alternately serve in closing, or partly closing,either the direct or indirect draft, as set forth.

HUGH M. PHINNEY.

Witnesses:

F. F. RAYMOND, 2d, A. J. OETTINGER.

